Aleksei Fedorovich Filippov (Russian: Алексей Фёдорович Филиппов; 29 September 1923 – 10 October 2006) was a Russian mathematician who worked on differential equations, differential inclusions, diffraction theory and numerical methods.
Born in Moscow in 1923, Filippov served in the Red Army during the Second World War, then attended Moscow State University (Faculty of Mechanics and Mathematics).
Filippov showed interest in continuous loops in 1950 when he constructed a proof that they divide a plane into interior and exterior parts.
[1] Known as the Jordan curve theorem, it exemplifies a mathematical proposition easily stated but difficult to prove.
[4][5][6] Filippov made an important contribution in the theory of discontinuous ordinary differential equations with his monograph Differential Equations with Discontinuous Righthand Sides (1985).